code: def get_arg(op, arg_name):
      for arg in op.arg:
          if arg.name == arg_name:
              return arg
      mace_check(False, "%s arg is not exist" % arg_name)
  
file_path: mace/tools/python/utils/net_util.py
imports: from py_proto import mace_pb2
  from utils.config_parser import DataFormat
  from utils.config_parser import DeviceType
  from utils.config_parser import Platform
  from utils.util import mace_check
  from transform.base_converter import PaddingMode
label_desc: Use image node_id 1 for calling the NetUtil obj's underlying member method code with example usage: obj.get_arg(op, arg_name) and returns: arg